In his new film “The Conspirator,” director Robert Redford digs into a little-known angle of one of the best-known moments in American history: the assassination of President Abraham Lincoln.

Instead of dealing with the shooting in the Ford’s Theater in Washington, already a movie subject, Redford takes aim at a back story to the 1865 assassination of the U.S. president — a complex plot that resulted in seven men and one woman being arrested and charged with conspiring to kill the president, the vice president, and the secretary of state.